This doesn't work because it would violate the law of conservation of momentum - the total momentum of the system before the event must equal the total momentum of the system after the event (assuming no outside forces). If we simplify the Earth/people system as stationary before the jump, the total momentum is 0. Thus, after the jump the system's total momentum must be 0 - which is possible only if system is stationary or the Earth and people have equal magnitude of momentum in opposite directions... in other words, the people jumped so hard they left the Earth (I guess those people really took one for the team then).

A participant (sorry, forgot who) shared another way to structure the activity is to have every student hold one card, then they must find their match.

A participant suggested a way to scaffold this activity: Give students just the written descriptions and have them read those. Then, give them the position vs. time graphs and have them match those to the written descriptions. Last, give them the velocity vs. time graphs to match to the existing pairs. (Or have them first set aside the ones they don't need yet.)

Slides - An amalgam of several iterations, so some slides may seem redundant, irrelevant, or out of order. The slides I showed at the workshop are the first 3 slides

After we analyze the class results, we usually conclude that ultimately air resistance prevents us from getting "perfect" results, so I show them some videos of experiments where air resistance is not a factor (below). This makes it easier to steer the conversation to the idea that all objects accelerate downwards at the same rate in the absence of air resistance. Then we discuss why.

Rubric - Someone asked for a rubric. I have two documents. First, a lab report checklist - many of my simpler investigations are graded using something like this. Second, a Claim Evidence Reasoning assignment. I barely remember doing this... I might have stopped doing this because I was getting dicey responses and wasn't sure how to proceed. Honestly, the whole CER thing has always been a challenge for me to teach.